Patent Application
20100300768
The present invention relates to a portable luggage scale. In particular, the invention relates to a scale that is inflatable, packable in luggage, and configured to allow a user to easily monitor the weight of a piece of luggage while packing and travelling.
Airlines recently have begun assessing fees for checking luggage and imposing costly penalties for checking luggage which is overweight. Frequently, travelers do not realize that their bags are overweight until they reach the ticketing counter at the airport where their luggage is weighed by airline personnel. Travelers who learn their luggage is overweight are faced with the choice of either paying a penalty or redistributing packed contents between their different pieces of luggage. Thus, there is a need for a convenient device which allows travelers to weigh their luggage both before leaving home and at their destination prior to their return home in order to speed check-in and avoid penalties and embarrassment.
Present scales available to the consumer for weighing personal luggage include the home bathroom scale type and the fish scale hanging hook type. However, the home bathroom scale requires a user to fully close the luggage and place it upright on the scale in order to read its weight due to the relatively small load platform and inconveniently located display. Such scales are usually heavy, sensitive, and not easily transportable. The fish scale type similarly requires a user to fully close the luggage before hoisting the luggage into the air with the scale's hook. Such a scale requires considerable strength on the part of the user and could cause muscle strain injuries. Both of these scale types require a user to fully close the luggage before weighing it, substantially impairing a user's ability to quickly and easily add or remove items from the luggage to reach a desired weight.
In addition, the load sensors typically used in these present scales are often expensive, increasing the cost of the scale substantially.
There is a need for an inexpensive, easy to use, lightweight, safe and packable scale on which an open piece of luggage may be placed and packed while allowing the user to easily monitor its weight during packing.
The present invention contemplates a portable scale which includes an inflatable bladder, an inflation port, a pressure sensor and a display. The pressure sensor and display may be mechanical or electronic. The bladder is inflated prior to use through the inflation port. During use, the pressure sensor senses the pressure inside the bladder and the display indicates the weight of an object placed upon the bladder as a function of the pressure sensed by the pressure sensor. After use, the bladder is deflated and the portable scale is easily stowed.
The portable scale may include a mechanical or electric pump. The mechanical pump may be attached to a hose connecting the mechanical pump to the inflation port or the mechanical pump may be integrally formed with the bladder. The electric pump may be attached to a hose connecting the electric pump to the inflation port. Alternatively, the user may inflate the bladder by blowing air into the tube.
The portable scale may further include controls for turning the pump on and off. The controls may be configured to turn the pump off when the pressure inside the bladder that is sensed by the pressure sensor reaches a predetermined level.
A deflation valve is provided for easily deflating the bladder for transport or stowage.
The bladder of the portable scale may also be attached directly to a piece of luggage.
The features of the present application can be more readily understood from the following detailed description with reference to the accompanying drawings wherein:
This application provides a portable scale for displaying the weight of a piece of luggage while it is being packed by a user.
In the invention, as shown in
The inflatable bladder 100 is configured to hold a gas, usually air, at a pressure at or above atmospheric pressure without leaking. The bladder is formed of flexible, air-tight material and sized to stably support a piece of luggage. An exemplary bladder may be formed of a vinyl material and may measure approximately thirty inches long by eighteen inches wide by four inches high when inflated.
The bladder 100 may have a shape of a rectangular prism, with side walls 108 and 110 formed perpendicularly to a top 112 and bottom 114 surfaces of the bladder 100. As shown in
The inflation port 102, is located in a surface of the bladder 100 and allows for the inflation and optionally the deflation of the bladder 100. The inflation port 102 is configured to prevent gas from entering or leaving the bladder 100 when not inflating or deflating the portable scale. Gas may be introduced into the bladder by a user blowing air into the bladder, a mechanical pump, an electric pump, or some other external source of gas.
The pressure sensor 104 communicates with the gas inside the bladder 100. The pressure sensor 104 may be mechanical or electronic. The pressure sensor 104 senses the pressure of the gas inside the bladder 100 during preparation and use of the portable scale 10. Examples of inexpensive pressure sensors suitable for use in the portable scale of the present disclosure are well known in the art.
The display 106 communicates with the pressure sensor 104 and is configured to indicate the amount of weight placed on the portable scale. The display 104 may be mechanical or electronic. The display 104 also may be an electronic digital display, indicating the weight as a series of one or more integer digits. An example of a digital display, as shown in
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An electronic display may also include a battery for powering the display and any alert, discussed in more detail below. The display battery may be a rechargeable type battery.
In operation of the portable scale, the pressure of a fixed amount of gas in a closed container and the volume of the container share an inverse relationship when the ambient temperature is held relatively constant. In other words, if the volume of the container decreases, the pressure of the gas increases with all other variables being held relatively constant.
As shown in
To increase the accuracy of the display, a calibration may be performed. The calibration provides an accurate description of the pressure to weight relationship of the portable scale. This relationship may not be purely proportionate and may instead be non-linear, as factors such as the material elasticity of the bladder, the shape or structure of the bladder and the compressibility of the gas in the bladder, among other factors, may influence the pressure change to weight relationship of the portable scale. Such factors may be accounted for by performing a calibration.
As shown in
To use the portable scale, the user first inflates the bladder by opening the inflation port and introducing gas into the bladder until the pressure inside the bladder reaches a predetermined level, as indicated by the display. Inflating the bladder to a pressure of slightly above atmospheric pressure generally is preferable. The predetermined inflation level may be indicated by a zero weight indication on the display.
Next, the user places the inflated bladder on a hard, flat surface, places the empty piece of luggage on the bladder and begins packing it. As the user packs, a weight measurement of the piece of luggage and its contents is continuously indicated by the display. Because the weight measurement is shown on the display while the user is packing, the user is able to easily keep the weight of the piece of luggage and its contents below a desired limit without interrupting packing to close or maneuver the piece of luggage in order to acquire the weight measurement.
When the user is finished weighing the piece of luggage, the bladder may be deflated and the portable scale packed up for easy transport or storage.
There are several alternatives for introducing a gas into the bladder. As shown in
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The portable scale may also include a battery for supplying power to the electric pump. The battery is desirably a rechargeable type battery. A battery charger may also be included in the portable scale for charging the rechargeable battery.
In addition to or as an alternative to a battery, the portable scale may also include a power cord and power plug for supplying the electric pump with power from a household power distribution network. To facilitate convenient use of the portable scale in countries with different power formats, power adaptors or transformers may be included as discrete components or integrally assembled in the portable scale. The electric pump may also include an electric motor configured to receive a power input in more than one format. Examples of such formats include direct current of various voltages or alternating current of various voltages and frequencies.
The electric pump may also be configured to deflate the bladder by pumping gas out of the bladder by reversing the input and output of the electric pump through a valve or other means.
The portable scale may include controls for turning the electric pump on and off. The controls may be in communication with the pressure sensor and may be configured to turn off the electric pump when the pressure sensed by the pressure sensor in the bladder reaches a predetermined level. The controls may communicate with an ON button 206, shown in
The function of the controls is shown in
In another embodiment, the portable scale may be incorporated in a housing 906, as shown in
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In another embodiment of the invention, as shown in
In describing examples and exemplary embodiments, specific terminology is employed for the sake of clarity in this disclosure. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner.
In addition, the embodiments and examples above are illustrative, and many variations can be introduced on them without departing from the spirit of the disclosure or from the scope of the appended claims. For example, elements and/or features of different illustrative and exemplary embodiments herein may be combined with each other and/or substituted for each other within the scope of this disclosure.
